The article discusses the essence of regional tourism product and its elements. Among them, narrow-gauge railways have been distinguished, as they often constitute a tourist attraction, provide an interesting way of spending free time or learning about monuments and nature, as well as serve as means of transport and a mainstay of railroading’s tradition and history. The aim of the article is to indicate the importance and possibilities to develop passenger service of narrowgauge railways in Poland as an element of regional tourism product. In order to achieve this, desk research method has been applied in respect to available literature and the results of secondary research conducted at the request of the Railway Transport Office and the Central Statistical Office. The analysis covers narrowgauge railways in Poland for the period 2014-2016. The article is of research nature.